Download or read book Performance Evaluation of Horizontal Wells With Multistage Fractures in Tight Formations by Considering Non Darcy Effect and Fracture Dynamics written by Liwu Jiang and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Performance evaluation of fractured wells has attracted increasing attentions since horizontal drilling and hydraulic fracturing technologies have been successfully and efficiently applied in tight formations; however, such an evaluation process is physically complex and mathematically challenging due to the composite effects of non-Darcy flow within fractures and fracture dynamics including complex fracture geometry, fracture network, and stress-sensitive permeability. It is of fundamental and practical importance to evaluate the production performance of a fractured well by taking the aforementioned composite effects into account in a consistent and accurate manner. A new slab source function was developed in the Laplace domain for improving the prediction accuracy on the early time transient pressure response which can take the fracture width into account. The semi-analytical method was used to solve the fluid flow problem through such hydraulic fractures each of which is discretized into small segments, while continuity equations at the interface of such discretized fracture segments were applied to generate the coupled matrix-fracture flow model. The effect of complex fracture geometry and shape-dependent conductivity on the transient pressure response are then examined and discussed. The fracture width is found to affect the early time transient pressure response, while the shape-dependent conductivity imposes a key impact on the transient pressure behaviour for the early and intermediate periods. A coupled matrix-fracture flow model is then proposed and solved in the Laplace domain with consideration of the aforementioned composite effects which may escalate the nonlinearity of the governing equations. An iterative method was developed to deal with the nonlinearity caused by non-Darcy flow in fractures, while the Pedrosa's transform formulation and perturbation technique is used to weaken and linearize the nonlinear effect caused by stress-sensitive permeability. It is found that the non-Darcy effect dominates the early time flow regime, while stress-sensitive effects in fractures and matrix mainly affect the transient pressure response for the intermediate- and late-stage flow regimes. The Laplace-transform difference method was further adopted to extend the current simplified fracture models more closely to reality by taking complex fracture networks into account. The fracture network is first discretized into small segments, and the finite difference method in the Laplace domain can be used to solve the fluid flow problem through such complex fracture systems. Furthermore, the effect of fractal-like discrete fracture network on the transient pressure behaviour can be examined, while the combined effects of complex fracture networks and stress-sensitive permeability can then be analyzed. Transition flow regime is identified for the scenarios with discrete natural fracture networks which can be affected by the stress-sensitive permeability in natural fractures. All the theoretical models have been validated and then extended to field cases. Type curves are generated and beneficial to examine the effect of each factor on the transient behaviour for horizontal wells with multistage fractures in tight formations under various conditions. The discrepancy between the real field pressure data and the traditional type curves without non-Darcy and stress-sensitive effects can be used to evaluate the degree of these two effects. Two new flow regimes including the fluid feed and transition flow regimes occurred in real field pressure tests can be employed to quantify the complexity of the hydraulic and natural fracture networks, respectively.

Download or read book Performance Evaluation of Wells With Single and Multiple Fractures in Tight Formations written by Feng Zhang and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modeling of Multi Stage Fractured Horizontal Wells written by Shanshan Yao and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Optimal Fracture Treatment Design for Dry Gas Wells Maximizes Well Performance in the Presence of Non Darcy Flow Effects written by Henry De Jesus Lopez Hernandez and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents a methodology based on Proppant Number approach for optimal fracture treatment design of natural gas wells considering non-Darcy flow effects in the design process. Closure stress is taken into account, by default, because it is the first factor decreasing propped pack permeability at in-situ conditions. Gel damage was also considered in order to evaluate the impact of incorporating more damaging factors on ultimate well performance and optimal geometry. Effective fracture permeability and optimal fracture geometry are calculated through an iterative process. This approach was implemented in a spreadsheet. Non-Darcy flow is described by the [beta] factor. All [beta] factor correlations available in the literature were evaluated. It is recommended to use the correlation developed specifically for the given type of proppant and mesh size, if available. Otherwise, the Pursell et al. or the Martins et al. equations are recommended as across the board reliable correlations for predicting non-Darcy flow effects in the propped pack. The proposed methodology was implemented in the design of 11 fracture treatments of 3 natural tight gas wells in South Texas. Results show that optimal fracture design might increase expected production in 9.64 MMscf with respect to design that assumes Darcy flow through the propped pack. The basic finding is that for a given amount of proppant shorter and wider fractures compensate the non-Darcy and/or gel damage effect. Dynamic programming technique was implemented in design of multistage fractures for one of the wells under study for maximizing total gas production. Results show it is a powerful and simple technique for this application. It is recommended to expand its use in multistage fracture designs.

Download or read book Low Carbon Technologies for the Petroleum Industry written by Kaiqiang Zhang and published by Frontiers Media SA. This book was released on 2021-11-24 with total page 245 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Reservoir Formation Conditions and Enrichment Mechanisms of Shale Oil and Gas written by Kun Zhang and published by Frontiers Media SA. This book was released on 2023-05-15 with total page 683 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Investigation of the Effect of Non Darcy Flow and Multi phase Flow on the Productivity of Hydraulically Fractured Gas Wells written by Nasraldin Abdulslam A. Alarbi and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydraulic fracturing has recently been the completion of choice for most tight gas bearing formations. It has proven successful to produce these formations in a commercial manner. However, some considerations have to be taken into account to design an optimum stimulation treatment that leads to the maximum possible productivity. These considerations include, but not limited to, non-Darcy flow and multiphase flow effects inside the fracture. These effects reduce the fracture conductivity significantly. Failing to account for that results in overestimating the deliverability of the well and, consequently, to designing a fracture treatment that is not optimum. In this work a thorough investigation of non-Darcy flow and multi-phase flow effects on the productivity of hydraulically fractured wells is conducted and an optimum fracture design is proposed for a tight gas formation in south Texas using the Unified Fracture Design (UFD) Technique to compensate for the mentioned effects by calculating the effective fracture permeability in an iterative way. Incorporating non-Darcy effects results in an optimum fracture that is shorter and wider than the fracture when only Darcy calculations are considered. That leads to a loss of production of 5, 18% due to dry and multiphase non-Darcy flow effects respectively. A comparison between the UFD and 3D simulators is also done to point out the differences in terms of methodology and results. Since UFD incorporated the maximum dimensionless productivity index in the fracture dimensions design, unlike 3D simulators, it can be concluded that using UFD to design the fracture treatment and then use the most important fracture parameters outputs (half length and CfDopt) as inputs in the simulators is a recommended approach.

Download or read book Well Productivity Handbook written by Boyun Guo, PhD and published by Gulf Professional Publishing. This book was released on 2019-07-31 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: Well Productivity Handbook: Vertical, Fractured, Horizontal, Multilateral, Multi-fractured, and Radial-Fractured Wells, Second Edition delivers updated examples and solutions for oil and gas well management projects. Starting with the estimation of fluid and reservoir properties, the content then discusses the modeling of inflow performance in wells producing different types of fluids. In addition, it describes the principle of well productivity analysis to show how to predict productivity of wells with simple trajectories. Then advancing into more complex trajectories, this new edition demonstrates how to predict productivity for more challenging wells, such as multi-lateral, multi-fractured and radial-fractured. Rounding out with sample problems to solve and future references to pursue, this book continues to give reservoir and production engineers the tools needed to tackle the full spectrum of completion types. Covers the full range of completion projects, from simple to unconventional, including multi-layer and multi-fractured well deliverability Includes practice examples to calculate, future references, and summaries at the end of every chapter Updated throughout, with complex well trajectories, new case studies and essential derivations

Download or read book Analytical Modeling of Multi Fractured Horizontal Wells in Heterogeneous Unconventional Reservoirs written by Jie Zeng and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Current analytical models for multi-fractured horizontal wells (MFHW) generally neglect reservoir heterogeneity, typical seepage characters of unconventional reservoir, partially penetrating fracture and various fracture damage mechanisms. In this thesis, three linear flow models have been developed to facilitate pressure and rate behavior analysis of shale, tight sand and unconventional reservoir with damaged fractures. These models are validated by comparing with KAPPA Ecrin and are more accurate than previous linear flow models in modeling partially penetrating cases. Field data are analyzed and results prove the reliability of these models. The first model is for heterogeneous shale reservoir with multiple gas transport mechanisms. It subdivides the reservoir into seven parts, namely, two upper/lower regions, two outer regions, two inner regions, and hydraulic fracture region. Fracture interference is simulated by locating a no-flow boundary between two adjacent fractures. The locations of these boundaries are determined based on the boundary's pressure to satisfy the no-flow assumption. Adsorption/desorption, gas slippage and diffusion effects are included for rigorous modeling of flow in shale. Sensitivity analysis results suggest that larger desorption coefficient causes smaller pressure and its derivative as a larger proportion of gas is desorbed in formation and contributes to productivity. The influences of other parameters, such as matrix II permeability, matrix block size, secondary fracture permeability, hydraulic fracture conductivity, and fracture pattern are also discussed. The second model is for heterogeneous tight sand reservoir with threshold pressure gradient (TPG). The linear flow sub-regions are the same as those of the first model. TPG and pressure drop within the horizontal wellbore are included. Simulation results suggest that TPG affects middle-late time behaviors. Greater TPG results in higher pressure drop and accelerates production decline. But this influence is marginal when TPG is small. Effects of other parameters, such as formation permeability, fracture length, conductivity, and wellbore storage are also investigated. The third model is for heterogeneous reservoir with various fracture damage. In this model, the following possible fracture damage situations are discussed: (1) choked fracture damage (2) partially propped fracture, (3) fracturing fluid leak-off damage, (4) dual or multiple damage effects. Simulation results indicate that choked frature damage influences early-mid time performance. Partially propped section within fracture dominates formation linear flow regime. Only severe matrix impairment near fracture face can have noticeable effects on pressure and rate response. A new parameter, skin factor ratio, is applied to describe the relative magnitude of multiple damage mechanisms. Reservoir heterogeneity and fracture damage make the pressure and rate behaviors deviate significantly from undamaged one but one can distinguish major damage mechanisms even in heterogeneous reservoir.

Download or read book The Performance of Fractured Horizontal Well in Tight Gas Reservoir written by Jiajing Lin and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Horizontal wells have been used to increase reservoir recovery, especially in unconventional reservoirs, and hydraulic fracturing has been applied to further extend the contact with the reservoir to increase the efficiency of development. In the past, many models, analytical or numerical, were developed to describe the flow behavior in horizontal wells with fractures. Source solution is one of the analytical/semi-analytical approaches. To solve fractured well problems, source methods were advanced from point sources to volumetric source, and pressure change inside fractures was considered in the volumetric source method. This study aims at developing a method that can predict horizontal well performance and the model can also be applied to horizontal wells with multiple fractures in complex natural fracture networks. The method solves the problem by superposing a series of slab sources under transient or pseudosteady-state flow conditions. The principle of the method comprises the calculation of semi-analytical response of a rectilinear reservoir with closed outer boundaries. A statistically assigned fracture network is used in the study to represent natural fractures based on the spacing between fractures and fracture geometry. The multiple dominating hydraulic fractures are then added to the natural fracture system to build the physical model of the problem. Each of the hydraulic fractures is connected to the horizontal wellbore, and the natural fractures are connected to the hydraulic fractures through the network description. Each fracture, natural or hydraulically induced, is treated as a series of slab sources. The analytical solution of superposed slab sources provides the base of the approach, and the overall flow from each fracture and the effect between the fractures are modeled by applying superposition principle to all of the fractures. It is assumed that hydraulic fractures are the main fractures that connect with the wellbore and the natural fractures are branching fractures which only connect with the main fractures. The fluid inside of the branch fractures flows into the main fractures, and the fluid of the main fracture from both the reservoir and the branch fractures flows to the wellbore. Predicting well performance in a complex fracture network system is extremely challenged. The statistical nature of natural fracture networks changes the flow characteristic from that of a single linear fracture. Simply using the single fracture model for individual fracture, and then adding the flow from each fracture for the network could introduce significant error. This study provides a semi-analytical approach to estimate well performance in a complex fracture network system.

Download or read book Fracturing Horizontal Wells written by Mohamed Y. Soliman and published by McGraw Hill Professional. This book was released on 2016-04-21 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt: Effectively Apply Modern Fracturing Methods in Horizontal Wells Improve productivity and maximize natural gas extraction using the practical information contained in this comprehensive guide. Written by world-renowned experts, Fracturing Horizontal Wells features complete details on the latest fracking tools and technologies. Illustrations, tables, and real-world examples are found throughout. Discover how to handle site selection and testing, build accurate simulations, and efficiently extract energy from horizontal sources, including shale formations. Environmental standards, regulatory compliance, and safety protocols are also included. Fracturing Horizontal Wells covers: • Fracture Stimulation of Horizontal Wells • Transitioning from Vertical to Horizontal Wellbores • Reservoir Engineering Aspects of Horizontal Wells • Reservoir Engineering Aspects of Fractured Horizontal Wells • Fracturing Horizontal Wells: Rock Mechanics Overview • Drilling of Horizontal Wells • Proppant and Proppant Transport • Fracture Diagnostic Testing • Interval Isolation • Horizontal Completion Fracturing Methods and Techniques • Use of Well Logging Measurements and Analysis for Fracturing Design • Fracture Treatment Diagnostics • Environmental Stewardship

Download or read book Optimization of Multi fractured Horizontal Gas Wells in Tight Formations written by Bezad Bagherian and published by . This book was released on 2012 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Optimization of Fractured Well Performance of Horizontal Gas Wells written by Fellipe Vieira Magalhães and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In low-permeability gas reservoirs, horizontal wells have been used to increase the reservoir contact area, and hydraulic fracturing has been further extending the contact between wellbores and reservoirs. This thesis presents an approach to evaluate horizontal well performance for fractured or unfractured gas wells and a sensitivity study of gas well performance in a low permeability formation. A newly developed Distributed Volumetric Sources (DVS) method was used to calculate dimensionless productivity index for a defined source in a box-shaped domain. The unique features of the DVS method are that it can be applied to transient flow and pseudo-steady state flow with a smooth transition between the boundary conditions. In this study, I conducted well performance studies by applying the DVS method to typical tight sandstone gas wells in the US basins. The objective is to determine the best practice to produce horizontal gas wells. For fractured wells, well performance of a single fracture and multiple fractures are compared, and the effect of the number of fractures on productivity of the well is presented based on the well productivity. The results from this study show that every basin has a unique ideal set of fracture number and fracture length. Permeability plays an important role on dictating the location and the dimension of the fractures. This study indicated that in order to achieve optimum production, the lower the permeability of the formation, the higher the number of fractures.

Download or read book Naturally Fractured Reservoirs written by Roberto Aguilera and published by PennWell Books. This book was released on 1980 with total page 730 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals exclusively with naturally fractured reservoirs and includes many subjects usually treated in separate volumes. A highly practical edition, Naturally Fractured Reservoirs is written for students, reservoir geologists, log analysts and petroleum engineers.

Download or read book Well Test Analysis for Fractured Reservoir Evaluation written by G. Da Prat and published by Elsevier. This book was released on 1990-11-19 with total page 221 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main purpose of this book is to provide the reader with a basic understanding of the behaviour of fractured reservoirs, using evaluation techniques based on processing pressure and flow-rate data resulting from production testing.It covers the fundamental reservoir engineering principles involved in the analysis of fluid flow through fractured reservoirs, the application of existing models to field cases, and the evaluation and description of reservoirs, based on processed data from pressure and production tests. The author also discusses production decline analysis, the understanding of which is a key factor influencing completion or abandonment of a well or even a field.The theoretical concepts are presented as clearly and simply as possible in order to aid comprehension. The book is thus suitable for training and educational purposes, and will help the reader who is unfamiliar with the subject acquire the necessary skills for successful interpretation and analysis of field data.One of the most important features of the book is that it fills the gap between field operations and research, in regard to proper management of reservoirs. The book also contains a computer program (FORTRAN language) which can be incorporated in existing software designed for reservoir evaluation; type curves generation, test design and interpretation, can be achieved by using this program.Petroleum engineers, reservoir engineers, petroleum geologists, research engineers and students in these fields, will be interested in this book as a reference source. It can also be used as a text book for training production and reservoir engineering professionals. It should be available in university and oil company libraries.

Download or read book Investigation of Hydraulic Fracture Complexity and the Benefits of Maximizing Or Minimizing Complexity in Unconventional Resources written by Rashid Sheikh Kassim and published by . This book was released on 2017 with total page 229 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This dissertation discusses two separate, yet inter-related studies. The first study was an extension of historical work comparing transversely fractured versus longitudinally fractured horizontal wells in multiphase flow environment. The second study investigated hydraulic fracture complexities and the benefits of maximizing or minimizing complexities in unconventional resources and tight reservoirs. The main objective of this research was to investigate fracture complexity and its impact on well performance and economics. To achieve that objective, three different integrated completions and reservoir models were built. Two of the three models, a hybrid reservoir model and micro-seismic based SRV (stimulated reservoir volume) model, were built to capture presences of discrete fracture networks (DFN). The results of the DFN-based models were compared to an integrated planar fracture model, which had bi-wing fractures with limited or no fracture complexity. The second objective of this research was to determine reservoir permeability based cut-off criterion that can be used as guide when selecting whether to drill transversely fractured versus longitudinally fractured horizontal wells in multiphase flow environment. The reservoir models built for the multiphase flow would also investigate the effects of stress dependent permeability, adsorption gas and non-Darcy flow effect. The third objective of this research was to develop a calibrated hydraulic fracture and reservoir model for the Montney shale, particularly for the Upper Montney Formation. This model would help companies select best lateral placement options in the Upper Montney, stage perforation targets and model-based stage spacing"--Abstract, page iii.

Download or read book Modeling Performance of Horizontal Wells with Multiple Fractures in Tight Gas Reservoirs written by Guangwei Dong and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Multiple transverse fracturing along a horizontal well is a relatively new technology that is designed to increase well productivity by increasing the contact between the reservoir and the wellbore. For multiple transverse fractures, the performance of the well system is determined by three aspects: the inflow from the reservoir to the fracture, the flow from the fracture to the wellbore, and the inflow from the reservoir to the horizontal wellbore. These three aspects influence each other and combined, influence the wellbore outflow. In this study, we develop a model to effectively formulate the inter-relationships of a multi-fracture system. This model includes a reservoir model and a wellbore model. The reservoir model is established to calculate both independent and inter-fracture productivity index to quantify the contribution from all fractures on pressure drop of each fracture, by using the source functions to solve the single-phase gas reservoir flow model. The wellbore model is used to calculate the pressure distribution along the wellbore and the relationship of pressure between neighboring fractures, based on the basic pressure drop model derived from the mechanical energy balance. A set of equations with exactly the same number of fractures will be formed to model the system by integrating the two models. Because the equations are nonlinear, iteration method is used to solve them. With our integrated reservoir and wellbore model, we conduct a field study to find the best strategy to develop the field by hydraulic fracturing. The influence of reservoir size, horizontal and vertical permeability, well placement, and fracture orientation, type (longitudinal and transverse), number and distribution are completely examined in this study. For any specific field, a rigorous step-by-step procedure is proposed to optimize the field.